Thailand (1993) Betel nuts on serving tray.
Stamps from the Malayan state of Penang showing betel nut trees.

The betel nut comes from the palm tree Areca Catechu which is a native of the Malayan peninsular. The Malayan state of Penang is named after the tree Pinang in Malay. The alkaloid arecoline is derived from the nut. When applied topically, it causes miosis and decreases the intraocular pressure.